Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.27K | Year: 2015
ABSTRACT:Heat transfer is an important quantity that remains difficult to predict using CFD. Phenomena such as transition and separation are difficult to capture with discrete sensors. Temperature-Sensitive Paint is an image-based technology that has been used for over 25 years to acquire measurements of surface temperature and heat flux in a variety of flows. The major limitation to deploying TSP systems in AEDC Tunnel B/C, where temperatures are between 600 F and 2000 F, is the availability of an appropriate TSP. Standard TSPs utilize polymer materials that will not survive long-duration testing at elevated temperatures while traditional phosphor-based TSPs employ coatings that cannot be removed without damaging the model surface. Recently, ISSI has developed phosphor-based TSP systems that address these issues. The TSP system is composed of a surface layer of a carbon compound that is over sprayed with a phosphor based TSP in a high temperature binder. The carbon compound adheres to the surface, but is non-reactive at elevated temperatures. Removal of the TSP system is accomplished using a Teflon spatula and then the carbon layer is removed using Acetone. The objective of this proposal is to deploy a TSP-based system for acquiring heat flux measurements in Tunnel B/C.BENEFIT:A system that can provide global measurements of heat flux on a model in a high temperature wind tunnel would be of value for future CFD validation and hypersonic designs. Temperature-Sensitive Paint is an image-based technology that has been used to acquire measurements of surface temperature and heat flux in wind tunnels. The major limitation to deploying TSP systems in AEDC Tunnel B/C, where temperatures are between 600 F and 2000 F, is the availability of an appropriate TSP. Recently, ISSI has developed phosphor-based TSP system that can be applied with an air-brush, operated at temperatures over 900 F, and removed with a Teflon spatula and Acetone. The overall objective of the program is to deploy a TSP-based system for acquiring surface temperature, heat flux, and heat transfer measurements in AEDC Tunnel B/C. The technical maturity and accuracy of the TSP technique has been demonstrated in numerous wind tunnel experiments. The potential to deploy a production data acquisition and processing TSP system is demonstrated by the commercial PSP/TSP systems that have been installed by the proposing team. It is noted that the market for TSP measurements in high temperature wind tunnels is limited, however, the fundamental technology that is key to the proposal, optical measurements of surface temperature has applications in a variety of markets. It is well known that gas turbine engine manufactures would like to deploy CMCs to both reduce weight and increase efficiency of these engines. Uniform film cooling of the CMC is required to prevent cracks in the CMC. An experimental system that could measure these temperatures on test rigs would be useful for evaluating the effectiveness of film cooling designs. ISSI is a key commercial source of PSP/TSP technology worldwide, with customers in the US, Japan, Korea, and several countries in the EU. Total sales from this technology are now over $1,000,000 per year with significant growth seen each of the last 6 years. Several commercial customers have expressed interest in a high temperature measurement capability. With our current market position, ISSI will be able to market this new capability to existing customers as well as develop new customers.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.91K | Year: 2015
ABSTRACT:The goal of the proposed effort will be to demonstrate a diagnostic technique that can simultaneously measure the combustion progress variable, the flow velocity, and the fuel-to-air ratio with high spatial and temporal resolution to allow the local heat release to be determined. This approach will require the combination of two well-established diagnostic techniques laser induced breakdown spectroscopy (LIBS) and laser acoustic anemometry (LAA). The former method will be utilized to measure local FARs, and the latter method will be employed to measure the speed of sound from which the local gas temperature and velocity can be determined. Once the local FAR, temperature, and velocity are known, the local heat release can be determined from thermodynamic principles. To accomplish this objective the following Phase I tasks are being proposed: Task 1. Construct and Calibrate LIBS System Task 2. Construct and Calibrate LAA System. Task 3. Construct Combined LIBS/LAA System. Task 4. Conduct Demonstration Tests in Large-Scale Atmospheric Burner. Task 5. Make Recommendations for Phase II System BENEFIT:The simultaneous measurement of FAR, temperature, velocity, and heat release is a significant step forward for the study of real-world combustors. The utilization of LIBS to measure combustion FAR has many commercial applications from automotive to industrial furnaces. The addition of the LAA system greatly increases the range of measurement capability and the usefulness of the experimental data. For example, combustion modeling typical utilized mixture fraction to determine flame characteristics (temperature, species, and pollutant formation) however, what they can only guess at is the local reaction progress variable. LIBS allows measurements of FAR but not the progress variable which requires in this case a simultaneous temperature measurement. The combined LIBS/LAA instrument provides both numerical and experimental combustor designers an important experimental tool that provides key experimental data for computational model evaluation.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.07K | Year: 2016
ABSTRACT:Quantitative ablation recession rate measurements of heat shield surfaces are essential for evaluating the performance of heat shield materials. Currently, these measurements are limited to two-dimensional images that focus on the nose tip regression rate. For wedge testing, recession rate is determined by comparing pre- and post-test measurements, and therefore, recession rate as a function of time can only be obtained by conducting separate tests with progressively longer run times. We propose a real-time 3-D surface mapping capability for arc jet models based on the concept of stereo photogrammetric reconstruction of the surface using projected structured light patterns onto the surface. Imaging in this high temperature reactive flow is degraded by emission from the surface and reactions in the flow which result in significant spectral content. Recently, ISSI has demonstrated image-based measurements of particle dynamics in Solid Rocket Motors using narrowband illumination and short exposure times to reject the broadband emission from the flow and surface. The resulting 3-D surface maps of material recession as a function of time would allow more effective ablation performance evaluations of advanced high-temperature materials and enable validation of computational models of material response.BENEFIT:It is noted that the market for ablation coating regression in hypersonic flows is limited, however, the fundamental technology that is key to the proposal, optical surface topography has applications in a variety of industries. A system that provides accurate measurements of surface geometry, even in the presence of noise may be of value aeronautical and bio-medical engineering. For ISSI, the most obvious customer base are existing wind tunnel operators who have an interest in higher performance model deformation systems. The surface-imaging systems that are key to this program could have significant impact on the model deformation applications. ISSI is a key commercial source of PSP technology worldwide, with customers in the US, Japan, Korea, and several countries in the EU. Total sales from this technology are now over $1,000,000 per year with significant growth seen each of the last 6 years. Several commercial customers have expressed interest in model deformation capability. With our current market position, ISSI will be able to market this new capability to existing customers as well as develop new customersts.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.92K | Year: 2015
Significant advances in the use of fast responding Pressure-Sensitive Paint have recently been achieved as demonstrated by a multi-camera fast PSP test conducted in the 16 foot transonic wind tunnel at AEDC. The unsteady pressure results from this test demonstrated excellent accuracy and spatial resolution, establishing the technical readiness of the fast PSP sensor. During the program, two issues were identified that would significantly improve the fast PSP system performance, 1) real-time data processing, and 2) acquisition of both mean and unsteady data using a single entry. Here we propose the continued development of the fast PSP system by addressing these issues. To enable real-time data processing, a system composed of a computer with a large block of memory, a multi-core processer, and several high end video cards (GPUs) has been assembled. Modern GPUs include thousands of floating point processors and large blocks of memory which enable parallel computations to be executed on individual images. Fast PSP data is an ideal application of this technology as many of the computations can be performed on each image independently. Preliminary tests by ISSI have demonstrated improvements of a factor of three to thirty in processing time using this approach. Acquisition of both mean and unsteady pressure during a single tunnel entry would increase tunnel productivity and can be used to improve the accuracy of the unsteady pressure data. Unfortunately, fast PSPs are generally very temperature sensitive which limits their use in acquiring mean pressure data. ISSI has recently developed a fast PSP formulation with low temperature sensitivity. This formulation will be optimized for use in large wind tunnels and enable acquisition of mean and unsteady pressure data using a single PSP.
Innovative Scientific Solutions, Inc. | Date: 2013-02-19
The present disclosure provides systems and methods for detecting arc faults. For some embodiments, arc faults are detected from waveforms that are acquired and processed, preferably using an Average Magnitude Difference Function (AMDF). The characteristics of the waveform provide an indication of whether or not an arcing fault occurred.